Affinity Design - placing curves into object does not work as intended?

[Gemini80]

In the attached video you can see me trying to place two curves into a circle - my intention was to place the lines into the circle so that they can't poke through if I resize them or position them differently. Unfortunately I must be doing something wrong - also, when I tried Boolean  add the the curves together they disappear - I am sure it is a user error situation and I'd be grateful for help! Thanks!

[Aammppaa]

1. The object that you are using to clip your lines is shown as a Donut. I think you have expanded the hole in the center so that it 'becomes' a circle. But it is not really a circle, but still a Donut. So when you drop the lines inside they are being clipped to an infinitely thin Donut, and hence disappearing.

To prove this, select the Donut with the Node tool. Grab the orange handle bottom left, and drag it to restore some thickness... and there are your lines, correctly nested inside.

I suggest replacing the Donut with an Ellipse (Circle) instead.

2. Simply put, you can't use Boolean operations on unclosed (open) curves: they disappear, as you discovered.

If you want the two curves to become a single layer, you can use Layer > Geometry > Merge Curves instead.

[v_kyr]

Well, if you clip the lines to the circle/donut, or instead make a compound of the whole (donut + lines) the lines can still be moved, resized etc. (when selected inside the clipping/compound groupings) if their layers aren't locked. - A geom add here for the donut + lines probably didn't worked, if your lines are plain strokes which haven't been expanded as strokes (...at least for ADe v1 it would behave like that here often). - Further why a donut instead of an ellipse?