Hi N0hva,
Welcome to Affinity Forums
Basically you have to create a new shape which is the sum of all internal shapes, subtracted from the main rose's outline shape. To do this you have to use geometric operations (boolean operation): to add shapes so they all become one, select them all (in your case the internal shapes inside the main outline) then go to menu Layer ▸ Geometry ▸ Add. Then select the rose's outline shape and the internal shape you just created and go to menu Layer ▸ Geometry ▸ Subtract (make sure the internal shapes are above the rose's internal shape in the layer's stack) or alternatively Layer ▸ Geometry ▸ Combine (in this case you can ignore layer's stack order) . You will end up with the shape of the rose filled with holes (the internal shapes) which you can fill as you want. You may want to duplicate all the initial shapes in case you want to work on them further as individual shapes.
