Cross-document link in Torrot table

I want to pull the torrot table with select tor_cat = TU documentation, same select tor_cat = FO documentation, is there a link between the two?

SELECT 
  tu_tor~db_key,
  tu_tor~tor_id,
  tu_tor~tor_cat,
  tu_tor~purch_org_id,
  tu_tor~zex_rlt_erp开发者_StackOverflow社区_ord_no,
  src_stop~log_locid,
  src_stop~stop_cat,
  src_stop~stop_role
  FROM /scmtms/d_torrot AS tu_tor 
  INNER JOIN /scmtms/d_torstp AS src_stop ON tu_tor~db_key EQ src_torstp~parent_key
    AND src_torstp~stop_seq_pos = @/scmtms/if_tor_const=>sc_stop_seq_pos-pos_source_stop
  INNER JOIN /scmtms/d_torrot AS fo_tor ON 
  

ı dont know what ı will write the code after ON. ?