When you have multiple engagements for the same Company, you may link Requests across those related Engagements.
Linking an existing Request
When you select the +Request button in any Sheet row, the Link Request window will default to Requests for the Engagement you currently have open. Select the Show requests from other Engagements checkbox to link an existing Request created in another engagement.
Linked Sheets from Multiple Engagements
If you have Sheets from separate Engagements linked and would like to Sync Requests, the method described above in Linking a Request across Linked Sheets would work here as well!