Hi, @LeonDemers,
There are a couple of approaches for leaders. You can copy-and-paste the date, and enter the requirements one at a time. This method will also work for parents & scouts. More efficiently, at least for me, is to use the Quick Entry tool:
My Dashboard → My Units → (scroll down) Quick Entry
You can enter multiple rank requirements, MB completions, awards, etc. I also have the Feature Assistant Extension installed, so there are a couple of additional quick-entry fields (I believe) that aren’t available without it.