How to Get Choices as a Dropdown from a different Column for the same Item In a Document Library?

Question

Hello All,
I was trying to see if there is any way that we can get the choices for a Field from another filed in the same item in a Document Library.
To be specific.
I have Created a Project Document Set, Which has a Column called "Project Members" where all the members will be listed. This will be inherited to all the documents in that Project Document Set. This is used to grant Permission using Workflow.
I also have "Document Members" Column(This is only for Documents) who will be given Edit permissions to that Document using a Workflow. This can be any type of column(choice, People or Group etc) As long as I can select multiple values.
I am looking for a way to get the "Project Members"(Values or Users) as choices for "Document Members". I know this is possible in the List as you can customize in the InfoPath Form. But not sure in the Document Library.
Document Members can only be the members from the Project Members, In order to grant granular Permissions for the project And Documents using a Workflow
Document Library
Project Document Set Name
File Name
Project Members
Document Members
Project A
User1;User2;User3
Doc1
User1;User2;User4
User1;
Doc2
User1;User2;User5
User1;User2;
Doc3
User1;User2;User6
User1;User2;User3;
Project B
User5;User6;User7;
Doc1
User5;User6;User7;
User7;User5
Doc2
User5;User6;User7;
User7;User5
Doc3
User5;User6;User7;
User5;User6;User7;
Thanks for your time.

Answer 1

>
Jenny Karunakaran wrote:
> Hi Jung,
>
> Thanks for the reply. But I dont know how to assign value set to this attribute(i.e. Context atribute to which filter value property is bound). Can I use a supply function for this ?
>
>
> Regards,
> Jenny
No. A value set and a supply function are two completely different things. You use this Context API to populate the value set for an attribute:
IF_WD_CONTEXT_NODE_INFO=>SET_ATTRIBUTE_VALUE_SET
Value Sets are also how ByKey UI elements (like the DropDownByKey) are built.  Here is a help document that discusses value sets - but in the context of the ByKey UI elements.  The process is the same for creating the value set however:
http://help.sap.com/saphelp_nw70ehp1/helpdata/en/bb/69b441b0133531e10000000a155106/frameset.htm