as a workaround:
add calculated custom field on user object:
{company}.{name}
use this newly created field for grouping.
To make this answer more complete, while text mode groupings are available, they won't work in charts (I'm 99% sure I've asked support about this).
If you don't want or cannot use custom field you can try this text mode grouping:
group.0.groupdatesby=WY
group.0.linkedname=direct
group.0.namekey=entryDate
group.0.notime=false
group.0.valuefield=entryDate
group.0.valueformat=atDateAsWeekString
group.1.name=
group.1.valueexpression={owner}.{company}.{name}
group.1.valueformat=string
textmode=true
with this as a result:

in chart you will still see company ID unfortunately.