And I did it like that. The point is that I use flexible field as options chooser. It looks like that:
I have repeater field. Inside of repeater I have: flexible-field “page-builder” and flexible-field “options”. Inside “Options” I have some layouts, for eg. “dimensions” or “colors”. Those options will work only for one repeater row, so I want to prevent possibility to choose “colors” more than once.
I use flexible-field because I don’t want to load unnecessary fields when they are not needed.