In one of the previous jobs I've used Jenkins Pipelines (and oh boy it was PITA to set it up in 2016) to handle jobs of different projects. On current one we are using Teamcity (still cheaper than Gitlab Silver license for us) which has the support of this feature as long as branch names have a common variable in their naming convention.
I.e. Project1 has branches in form feature/TICKET_NAME or fix/TICKET_NAME, Project2 uses only TICKET_NAME, TeamCity VCS settings are based upon masks of branch names so ticket 12345 would be branch 12345 in P2 but fix/12345 or feature/12345 of P1 if one exists (priorities could be tweaked too).
I.e. Project1 has branches in form feature/TICKET_NAME or fix/TICKET_NAME, Project2 uses only TICKET_NAME, TeamCity VCS settings are based upon masks of branch names so ticket 12345 would be branch 12345 in P2 but fix/12345 or feature/12345 of P1 if one exists (priorities could be tweaked too).