When we stage a campaign from search query and select “manager” as reviewer, The line items of the identities who don’t have manager will get reassigned to the user who created the campaign.
is there a option to configure this fall back approver when a manager is not there.
I don’t think if this options exist.
But after your campaign are create, you can achieve it programmatically by using for example a script assign the owner of reviews to another identity.