Query on multiple fields ("field 1 and field 2")

I’m trying to query the content API on 2 fields.

cms.cmsClient.getEntries({
                content_type: 'Group',
                'fields.siteArea': 'Corporate',
                'fields.siteSubArea': 'Work for us'
})

However, this doesn’t seem possible, however, it seems like a fairly basic thing to be able to do.

Ah! my content type should be ‘group’ not ‘Group’