Value lists- re-using previous choices

Hello once again,

After some time away from this forum, I've chosen to revisit & streamline my current travel agency related FM solution even further to make data entry more efficient. I've encountered a small problem while not critical but is annoying/time consuming; for this I need your wisdom.

Situation as follows:

From my drop down value list of contact names (containing hundreds of them), via a portal, I assign 3 participants to an airline booking... let's call them x, y, z. To do so, via a portal, I scroll thru the dropdown value list to find participant x. I then repeat same process to find participant y & z. Tedious to say the least.

This whole process is then repeated when applying a payment by each participant to the booking. Rather than once again scrolling thru hundreds of names in the value list to find participant x, then y, then z, could the value list update to just reflect the 3 previously chosen participants x,y & z?

Is there an easier way? Could I have the previously chosen participants retained for use when assigning individual payments?

Your sharing of time & knowledge is appreciated.

Jack