I'll try to answer your question. Sorry if it doesn't satisfy you (keep in mind that i won't address refugees/migrants fleeing from conflicts because that would be counted as 'forced' immigration). Most of the time, if you're a freeman/worker/artisan that isn't tied to any land you can. Economic migration to urban centres was common with relatively little regulation in the 16th to the 17th century. Istanbul, for example was a prime attraction for migrants all across the empire. Albanians worked in the gardens just beyond the city walls, maintaining pavements of Istanbul's streets, and serving as an irregular or armed guards in the household of an important person. Jobless Dalmatians periodically left the Venetian domain and found employment as gardeners in and around Istanbul, Workers from Kayseri figured prominently on construction sites, Greek migrants set up general stores in the Eyüp area, and people from the Maghreb and Morisco refugees often worked as fezmakers. Some of them were settled, while some only lived there for the job for around five to seven months and returned to their original hometown afterwards. Though to my knowledge, most people don't travel as long as you stated (Bosnia to Damascus, Tunis etc) but there were cases of that, for example in the 18th century we have numerous residents in Arab provinces that bears the surname Bushnaq (Bosniak) and there were Croats and Montenegrins working in coalmines of Zonguldak in the 19th century.

These migrations, of course had some regulations though as i said is rather limited and often not really enforced. Migration had to be undertaken in groups, best is to come as part of a circle of colleagues, and sometimes the migrants were expected to provide sureties that would guarantee their appearance in court if demanded. Eventually some migrants formed separate guilds or joined the available one. Possibly some of the older men on retirement called on their sons or nephews to replace them. Often, if a person did not attach himself to such a recognized group or guild, he risked eviction as an illegal immigrant. There are times in the where officials restricts immigration, especially during plagues and crises where a possible over-use of the capital’s limited food and water supplies and the maintenance of public order were of important issue. In those times, road blocks were often set up at which travellers had to state their business before they could proceed and undertaking periodic raids for illegal immigrants within Istanbul were the usual actions devised to counteract immigration. In the 18th century, because of various crises immigration control tightened or outright banned, though this was mostly enforced on Balkan or Anatolian migrants fleeing from disorders or the armies of Austria and Russia. The administration de facto tolerated the immigration of organized groups in well-defined lines of work or is attached to a guild (because otherwise the political elite would soon complain about labour shortages). On the other hand, provincials ‘on their own’ who might end up joining the capital’s marginal men were to be kept away as far as the practical means of the time permitted

Sources:

Artisans of Empire, Crafts and Craftsmen Under the Ottomans by Suraiya Faroqhi

The Ottoman Empire, 1700-1900 by Donald Quataert