Each mark requires its own test.
The Mark of the Guildsman is reserved for those who pass the Trial of the Guildsman. You must be above level 35 to qualify. To take this test visit Warehouse Keeper Valkon of the Town of Giran.
The Mark of Prosperity is reserved for those who pass the Testimony of Prosperity. You must be above level 37 to qualify. To take this test visit Warehouse Keeper Parman of the Town of Giran.
And last, the Mark of the Searcher is reserved for those who pass the Test of the Searcher. You must be above level 39 to qualify. To take this test visit Master Luther at the Hunters Village.