Notification to a multiple recipiants

Hi there, I have a question and i’m not sure if this is the correct place to ask.
how can i send a notification to a more than 1 ios device, i know i can create a group, but not always i will send to the same members of that group, example:
notify if door is opened, notify to membe1, member2 and member4, but tomorrow member2 is on a trip so i need to remove it from the script.

thanks for your help