Get User's Roleassignments / Office 365 group permissions REST API

Question

I have added users to a Office 365 group but I can't see which users are in which group using the Sharepoint API. When I query currentuser?$expand=Groups it's empty but when I ask the roleassignments on a object/list I get my defined groups as Security Groups.

Example for the group Developers:

<entry>
      <id>https://promissiebv.sharepoint.com/_api/Web/RoleAssignments/GetByPrincipalId(15)</id>
      <category term="SP.RoleAssignment" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" />
      <link rel="edit" href="Web/RoleAssignments/GetByPrincipalId(15)" />
      <link rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/Member" type="application/atom+xml;type=entry" title="Member" href="Web/RoleAssignments/GetByPrincipalId(15)/Member">
         <m:inline>
            <entry>
               <id>https://promissiebv.sharepoint.com/_api/Web/RoleAssignments/GetByPrincipalId(15)/Member</id>
               <category term="SP.User" scheme="http://schemas.microsoft.com/ado/2007/08/dataservices/scheme" />
               <link rel="edit" href="Web/RoleAssignments/GetByPrincipalId(15)/Member" />
               <link rel="http://schemas.microsoft.com/ado/2007/08/dataservices/related/Groups" type="application/atom+xml;type=feed" title="Groups" href="Web/RoleAssignments/GetByPrincipalId(15)/Member/Groups" />
               <title />
               <updated>2016-06-24T10:08:27Z</updated>
               <author>
                  <name />
               </author>
               <content type="application/xml">
                  <m:properties>
                     <d:Id m:type="Edm.Int32">15</d:Id>
                     <d:IsHiddenInUI m:type="Edm.Boolean">false</d:IsHiddenInUI>
                     <d:LoginName>c:0o.c|federateddirectoryclaimprovider|907f7cf0-03e4-444f-b6fd-481a6d76e428</d:LoginName>
                     <d:Title>Developers</d:Title>
                     <d:PrincipalType m:type="Edm.Int32">4</d:PrincipalType>
                     <d:Email>[email protected]</d:Email>
                     <d:IsShareByEmailGuestUser m:type="Edm.Boolean">false</d:IsShareByEmailGuestUser>
                     <d:IsSiteAdmin m:type="Edm.Boolean">false</d:IsSiteAdmin>
                     <d:UserId m:null="true" />
                  </m:properties>
               </content>
            </entry>

How to know which Sharepoint user has access to which Security Group?

Thanks

Answer 1

You can use RoleAssignments to get all users in all groups. Your post inspired me to figure it out.

../api/web/RoleAssignments/Groups?$expand=Users