Custom rig for retargeting

Someone has experience creating custom rig for retargeting? Where can I find examples… Only Humanoid rig is available but any Paragon Character has own rig for retargeting… For Example ParagonGideon

rig.png

Thanks. You saved my time… And one more question, can i add some offset between source and target bones?

Thanks. I found the answer in this playlist on the Unreal chanel, change translation retargeting options and some correction in the blueprint.