In the various levels of the non-league pyramid, from the National League North and South down to such as the lower division of the Northern Counties East League (e.g., Brigg, Skegness) clubs are re-arranged when necessary following promotion and relegation in order to try and maintain geographical groupings.
Apart from switching clubs between divisions in the same league, e.g. from the Southern League Premier Division Central to the South Division this sometimes includes switching them between leagues, e.g. between Southern League and Northern Premier League.
In the old days of the Football League's regionalised Third Divisions you'd get clubs like Walsall or Port Vale which would be switched between North and South. according to whichever clubs had been relegated (or, occasionally, elected).