I have two container figures (Block) and some smaller figures (Process)
inside. I want to connect the smaller figures in different Blocks, but
when the connection reaches the border of the Block it disappears.
How can I force the Connections to be always on top ?
Add connections to a layer above the layer where you've placed the shapes.
There's a CONNECTION_LAYER defined on ScalableRootEditPart. Put your
connections in that layer. See logic and shapes example editors.