I used to be the cubmaster of a pack. When my son crossed over to the troop I became a committee member for the troop and dropped my affiliation with the pack in scoutbook. Even after two years now though, the 6 or so scouts that all came over from the pack to the troop show up in the troop level and somehow retained my ability that I could go in and check them off on things. The remainder of the troop is not open to me accessing it.
You can remove your connection to these Scouts or have one of your Unit admins do it, or modify it. A Committee Member is a Leader in the Troop, and ScoutBook will allow any Leader with Edit Advancement connections to make Approvals.