Have the dates, continuity, qualifying capacity and relevant three-year period assessed. Do not assume that any prior service counts, or that returning to the company automatically erases a potentially relevant earlier year.
Evaluate the history rather than a single tenure total
Provide the actual foreign employment periods and intervening circumstances. The knowledge requirement and the qualifying foreign year remain separate issues; long familiarity cannot cure a missing continuous qualifying period. The point that decides these cases is rarely the total years of service; it is whether one continuous qualifying year sits inside the relevant preceding three years.
Two records settle it: payroll evidence covering the period claimed, and documentation of the employing entity for each stretch. Where a person left the group and returned, the intervening employer matters as well, since work for an unrelated company neither counts nor necessarily breaks anything else the file needs. What goes wrong is a shortcut in the other direction, namely assuming that because an earlier period is old it cannot help.
It may sit inside the relevant window depending on when the assignment would begin, so establish the dates before deciding what is useful. Bring the question to counsel as a timeline rather than as a conclusion, and let the applicable rules select which period is relevant. A missing month is easier to locate now than after a request for evidence arrives.