Get store item in Effect

I have a small Effect and I need to get the action data (nanoId) and I need to select data with this nanoId in store:

  syncObj$ = this.actions$.pipe(
    mergeMap(({nanoId, obj}) => {, first())).subscribe(eObj => {
        // return [] <-- error if I try to return pipe result here and remove return below
      return [] // <-- this is below return

I thought of withLatestFrom() but it needs an additional pipe, as I understand.
My goal is to catch an object and nanoId from action, then select an object with nanoId in store (eOnj) and compare some of it’s fields. Thanks!

Source: Angular Questions