Just out of curiosity assuming that the store manager and assistant store managers aren't there who is the highest-ranking employee or who is in charge.
the assistant manager is in charge and if they aren't there, it's usually a front end manager or another department head. in the night time it's the night lead who's in charge.
If the grocery manager is there, it'll be them. If not, most likely a front end manager. If not them then really any dept. head who is in the store at that time.
During Nights, Center Store Lead (Night Lead - Second shift 3 - 11) is in charge of the store and is a key-holder as management is pretty much gone by 7PM. But if Grocery Ops Manager is there, then GOM is in charge with CSL assisting them.