*--Suggestion needed with validations--*

For example we have two tabs made of rich text fields one beside the other.

*Company Details    * Employee Details

Step 1: User clicks on company details and fills the form and the validation message triggered for  few of the fields in editbale grid.
Step 2: After filling company details (Contains errors), user clicks on employee details and fills the form(Contains no errors).

Now user is on emplyoyee details page and when user clicks on submit (skipValidation:false), the form gets submitted even though there are errors in company details tab.

Note:
Company details and employe detials are two sections with two diffrenet interface rules, which are called using if() when user clicks on tabs.
User can go to any tab at any time and fill the form.

There are around 15 tabs, each tab has editbale grid with 10 to 20 rows each.As the form will be huge do we divided them into tabs.

Scenarios Tried:
1.Validation Group Doesnt work.
2.Used Button widget with name "Validate" and captured all the errors and shown the errors at top.(This is one possible solution but bit confusing to user)
3.Used button widget submit with name "Preview" and once user clicks on it will be navigated to other screen with all the  tabs
 one below the other, so that user can see errors in next screen (This is second possible solution but there is performance concern as this will be huge form combining all tabs one below the other)

Please suggest  possible solutions.