First part: called joint (legal) rather than shared custody in E&W = England & Wales, with physical care & control going to either parent or guardian.

Second part: placement, as used in job and au pair girls or *boys*, might connote a foster or adopted child.

US AmE website: 'Most custody orders 'divvy up' (divide up?) custody in one of the following ways: sole legal custody and sole *physical custody* (E&W: care and control) to one parent sole physical custody and joint (shared) legal custody joint (shared) physical custody and joint legal custody, or sole legal custody and joint physical custody (rare).'

This answer might work in the UK (and Hong Kong), but not necessarily elsewhere e.g. USA or Canada.

PS I crave indulgence for any blind spot caused by English family law taught badly, albeit half a century ago, by a prudish Englishman Solicitor, the worst law lecturer I ever had.