I am developing a customer application form using OmniScript and need to populate a dropdown in an Edit Block with a specific list of accounts.

The OmniScript is related to an Opportunity, and I have an Extract data mapper which gets the IDs of all accounts associated with the Opportunity account (e.g. if Opportunity is associated with a Household account, the data mapper pulls IDs of all household members).

The first step of the application form allows users to check and correct contact/account details for all household members using an Edit Block. This is populated using the data mapper and works as expected.

Subsequent steps allow creation of other records related to these accounts (e.g. employment history). For this I am also using Edit Blocks, but I need a dropdown field in the Edit Block to associate these records with a specific applicant.

I have followed the tutorial at this link to create a custom Apex class which populates the dropdown with ALL accounts in the Salesforce instance: /@anthima/dynamic-dropdowns-customizing-picklist-values-based-on-select-properties-in-omniscripts-a112c66f0c12

How can I modify this Apex class to only retrieve the relevant accounts, i.e. the IDs already retrieved by the data mapper? It's my understanding I can only populate a dropdown using Apex and cannot leverage the existing data mapper.

I am new to Apex - advice or other suggestions appreciated.