reqSet

% Load a new requirement set file and select one referenced requirement
rs = slreq.load('C:\MATLAB\My_Requirements_Set_1.slreqx');
allRefs = find(rs,'Type','Reference');
ref = allRefs(1);

% Query which requirement set ref belongs to
reqSet(ref)

ans = 

  ReqSet with properties:

             Description: ''
                    Name: 'My_Requirements_Set_1'
                Filename: 'C:\MATLAB\My_Requirements_Set_1.slreqx'
                Revision: 65
                   Dirty: 0
    CustomAttributeNames: {}