seyed

Yes, we need a "Transform Each" pretty badly!!
@seyed
My advice: Take the dots into Inkscape. You'll be done in 30 seconds. Bring the result back into AD if you want. This is a true edit each solution.
But, If you want to stay exclusively in AD: There's no reason to have to do these individually by hand. (well maybe a couple of them, because in your example if you increase the dimension by that much some of the dots will overlap which will cause a problem in a group operation.)
BTW, The reason you're getting a "hole" in the middle is because the stroke is greater than the dot radius and crossing over itself. In this case ignore it . 
(the following is just one way to do it..... also assumes you do NOT want a hole in the center... but, that wouldn't be a big deal either)
1) select all dots (btw these aren't perfect circles.... is that correct?)
2) make the stroke whatever you want. (Ideally(?) to the point of no dots overlapping. Ignore the "hole".)
3) Expand stroke (to all at once).
4) Boolean Divide (again to all at once).
5) Boolean add (again to all at once).
If the desired target size causes overlap, those areas will need individual attention.
And it goes without saying..... this is not an all purpose solution and definitely not a suitable substitute for a dedicated Transform Each function. 
(in the GIF I give the dots a fill just to show that the "messed up" stroke on the inside is there. It's not a step in the process)
Edit: just came back to say that if you do have a fill when doing this there will be circles left underneath the new Curves item that will need to be deleted. No fill.... no worries.

reglico,
That's a nice workaround, notice however that all objects with FX effects applied are rasterised on export. This may or may not be important for the user.

The OP has now created such a thread here.

Yes, I am missing this feature almost every day. All workarounds have their limitations. 

Yeah, that is weird, I am looking at it now and I think you've found a bug regarding the small size of the dot/ellipse getting an offset for the stroke after it reaches a certain size.

Hi seyed,
Welcome to Affinity Forums
Currently there's no way to resize multiple existing objects individually keeping their current positions. I advise you to add this to the Suggestions for Affinity Designer on Desktop section.

Are all the image the same dimensions?
If Yes
Leave the images stacked, select them all and set their height to 102px in the transform Panel If you don't have this icon on your Toolbar along the top, add it by right clicking on the Toolbar and selecting Customise Toolbar Now select the Alignment icon  
Why does it say Customize Toolbar and not Customise Toolbar, I thought this was a UK based app?

If you can select all of them by drawing a marquee around them with the Move Tool, you should then be able to drag the nodes of the selection box to resize them all.

If you create a symbol from a vector shape, changing any instance of the symbol should simultaneously change all other instances which are still synced. Doesn’t that happen for you?

Welcome to the Affinity Forums, sumneuron. :)
 
All of the tools do have an easy way to type in the size of the object: use the W and H controls in the Transform panel. If you draw a regular pentagon (by holding down the Shift key as you drag out the shape) you'll get a square base box which is slightly bigger than the overall height and width of the shape it contains, so you need to convert the shape to curves before you can adjust the width and height accurately.

It's on its own "Object" Layer, aptly named (Cog), I could put it under a Parent Layer so that I can have a collection of objects and filters or I can have them under a Group Layer. Personally I prefer Group Layers.
 
one thing that does bug me is the use of colour id for a "Layer Layer" and the minute line that shows that colour, just colour the whole Layer or have a clear block of colour indicating its coloured designation. As it is its next to useless.
This would be better, I'm quite liking the gradient one actually.

 

If you think everything is a layer it can be confusing but the layers are named clear enough.
 

You need to actually create Layers in the Layers Panel and place/create the objects into those layers.
 
Yeah, it's confusing because Serif saw fit to call any/every object a layer, but they are not. They are objects.

Take a look at this file and it's exported PDF
Untitled.afdesign
Untitled.pdf

Your file has artboards, no layers.
 
The attached AD file and resultant PDF has layers.
 
Mike
4-layers.afdesign
4-layers.pdf

If you open the PDF in Affinity Designer (ADe) the arrangement is the same as the .afdesign document, the pdf also has 4 pages

There are no layers in your AD file nor in the resulting PDF. Period. 
 
Open my PDF in Acrobat or Reader. There are layers in the PDF.

I know Mike, I should have explained more  I was just showing how Artboards work and how you can have variations on a theme by copying over all of the objects to another Artboard to simulate different approaches to the same problem. Also to show how Artboards simplify PDF page export.

I like playing as much as anyone.
 
But when someone is reporting a possible bug, try to stick with the reported issue using the same application. 
 
Mike

Just been playing with an online app called Draw.io, I have used Seyed's design to play with it and then I exported what I made to SVG and tweaked it in Affinity Designer (ADe), another tool in my arsenal lol!

 
Untitled Diagram-5.svg