It is possible to do a one-way mapping of a picklist in Luminate CRM (or Common Ground Enterprise) to a text field in Luminate Online, but you cannot map a drop-down field (eg on a Donation Form) from Luminate Online to Luminate CRM/Common Ground Enterprise.  Because of the way data is stored in both products, there is no guarantee that the data will come across the way you want it to.

Also, you cannot map a multi-select picklist from Luminate CRM to Luminate Online, because there is not a similar data structure in Luminate Online to receive that data.