Is there a way to add existing items to a plan?

[Susan Eide]

I have seen the other notes about going into source issue and editing that but that is pulling the master board and not my individual plan. My team has multiple plans that make up a portfolio & if I make a new Epic and want to add it to my portfolio, the only way it seems possible to do this is by excluding the other epics with no plan from my plan. Seems like there should be an easy way to link this.