Understanding Society User Support

I am interested in using the wave 2 main interview data linked to the nurse assessment data on biomarkers for this sample only (i.e. I am only interested in the GPS sample, not combining with the BHPS sample who had their nurse assessment after wave 3). I understand from the Nurse Assessment user guide that I should use the weight variable 'b_indnsus_xw' for this type of analysis. However I cannot seem to find this variable in the wave 2 main data or the nurse's assessment data. Would you be able to advise where it can be found? Many thanks.