On you table have a formula field which displays the first 8 digits and a linked field to a “Lots” table:
Set up an automation that copies the 8 digit lot string into the Lot linked field when the Name field is populated:
Now in your interface, you can add a filter that allows you to select the Lot linked field:
This doesn’t give you a single select drop down, but the linked field modal is pretty easy to find and select from (and it stops you have to type in the lot number). A linked field is also better if, for example, you want to count how many products you have in that lot, which you can’t achieve with a single select
@Jed_Davidow You can do it manually if lots are more or less stable data. Add a single-select field, then copy a column with calculated lots and paste it into the newly created single-select field.
If you need instant updates of this field, then use automation to copy each time when the record is created.