Hi,
If validations are different, then there's no guarantee from a PPM Server perspective that the fields will be identical, even though you may have done your best during configuration to ensure that it's the case.
If you're not afraid to get your hands dirty with a bit of code then it's always possible to leverage the DM REST API to retrieve the TC value from one request, and insert it in another request TC field - if columns are indeed the same between the two TC validations, then you shouldn't have to change too much in the JSon payload to get it to work - but that is not something I would expect a normal business end-user to do obviously. Are you familiar with PPM REST APIs?

Note that in next PPM version we may introduce a capability for Excel Import/Export for Table Components, but unfortunately this will come with two limitations that will block the usage in your scenario:
1) Importing TC through Excel bypasses all UI & SQL Rules as we have no reliable way to control what gets entered in Excel - and this will likely be a blocker for most situations.
2) We're only allowing to update a TC from Excel if the excel file was initially generated from the same request type and field (possibly from a different request, though you'll get a warning message). This also means that we won't let you import data between two different TC fields of the same request even if they use the same validation - so, in your case where you even use different validations, that will be even less possible. Now, the thing is, you will be able to edit the excel file contents to "cheat" controls and import data anyway, but that won't really be the intended behavior. Still, easier for a PPM user to edit a hidden row in an Excel file than to call PPM REST Services !

Thanks, but I have no experience with PPM REST APIs . . .

Thanks, but I have no experience with PPM REST APIs . . .