MS Access to PostgreSQL

I have recently migrated from MS Access to PostgreSQL.Previously I had
a SQL command

ResultSet aGroupResultSet = aGroupPathStmt.executeQuery(
"SELECT \"groupID\",\"fullpath\" FROM \"groups\" WHERE
\"fullpath\" Like '" +
aPath + "'");

where aPath was equal to 'folder\another folder\%'.

The field to be edited stores the full path in the format
'folder\folder1\folder2' and so on...
The purpose being to change all groups at this level of the
hieracarchy and below, this was achieved using the '%' in Access, this
however doesn't seem to work in PostgreSQL, it doesn't error out but
it just seems to see the '%' as a normal character.

How can this be done in PostgreSQL?

Many Thanks,
B