Dialog prompt to provide selection of team the use


I need to figure out how to accomplish this;

1. During the creation of a record when an account is assigned to a user i.e. User A, the system will either “prompt to provide selection of the teams that the user (User A) belongs to”

2. If the user is assigned to a team, the system will do nothing (simply because the business requirements stipulate that every record must be owned by a team rather than individual user)

Whats the best way to accomplish this without (code) development? Is it possible to do this with a dialog? If so what are the steps?

Hope you can help,