I have this query in sqlserver with 2 tables(one contains a list of companies, the second contains a list of publishers)

with edges as (
      select t1.company as node1, t2.company as node2
      from table1 t1 join
           table1 t2
           on t1.publisher = t2.publisher
     ),
     cte as (
      select e.node1, e.node2,
             cast('|'+e.node1+'|'+e.node2+'|' as varchar(max)) as nodes,
             1 as level
      from edges e
      union all
      select c.node1, e.node2,
             c.nodes+e.node2+'|',
             1+c.level
      from cte c join
           edges e
           on c.node2 = e.node1 and
              c.nodes not like '|%'+e.node2+'%|'
     ),
     nodes as (
       select node1,
              (case when min(node2) < node1 then min(node2) else node1 end
              ) as grp
       from cte
       group by node1
      )
select t.company, t.publisher, grp.GroupId
from table1 t join
     (select n.node1, dense_rank() over (order by grp) as GroupId
      from nodes n
     ) grp
     on t.company = grp.node1;

I should convert this sqlserver query into postgres