Help me to define rank

[Robyrubyjane]

hi guys I need help, so i have data like this..

and if I filter one of data in sitename column, it'll be like this..

as we can see there is 4 sitename that has same name and SiteID but each them have different sonumb, so in the column tenant rank i want it'll rank based on the oldest date, like this

if we clear the filter, it'll be like this...

and if I sorted by SiteName, It'll be like this..

there is 15k data in my masterlist, and it'll take lots of time if I input tenant rank one by one which is that I have to filter each siteID to see is there only 1 siteName or maybe more that actually has different sonumb. so do you guys know the formulas or VBA for this problem, I've been looking for answer like a week and still haven't find the answer :'(


TIA!!

 

[awoohaw]

Are sonumb generated by date and are ascending? And are they numeric?
I think you can sort first by sonumb, then your site ID and they will be grouped in the sort siteid, then sonumb.