How to configure values for mapped fields
Purpose
We'll discuss how to map picklists values. The following are the rules to keep in mind when mapping or configuring values.
Answer
Bi-directional mapping has a one-to-one relationship.
If the field binding is in only one direction, values could have a one-to-many relationship.
If the same value is mapped twice, it is also impossible to convert from single-directional field mapping to bi-directional.
When mapping picklists values, the sync goes by API name in Salesforce
Note: Salesforce Picklists fields allow admins to restrict or allow values other than what's defined in the value set. If “Restrict picklist to the values defined in the value set” was set to false, this allows for values from outside of the list to appear on the dropdown.