LISTAGG using different order columns within group

[riteshm]

if we create a measure of type: list, is there a way to change the order by clause of the listagg in the query that looker generates ?
a general syntax of listagg would be 
LISTAGG( [ DISTINCT ] <expr1> [, <delimiter> ] ) [ WITHIN GROUP ( <orderby_clause> ) ]
How can we have multiple objects in the order by clause ?
ex: listagg(distinct hire_date, ‘, ’) within group (order by emp_id, dept_id)

Along with this, can we change the delimiter of the listagg ? Looker generated query uses '|RECORD|' in the generated query which translated to a comma on the report UI