You can set the data source of the reference selector as a microflow and then in that datasource microflow you can set the association to whichever value you need to use as a default value.
I suppose you want to set a reference for an entity?
If this is the case, you can set the default value of the reference when the entity is created.
Which means you have to build a microflow in which you are retrieving your default value and create your new entity. After creating your entity you can set the reference to your value.
value means in this case the other object which you want to reference.
I have done it. set reference value and only be set using association object totally. that means, you shoud create a association object firstly ,then in this association object insides, set the attribute to the wished value, then assign this association object entirely to the call object’s memeber association.