This achievement should be done after doing the Darkness Returns quest. To get this achievement you have to do 5 quests from Delvin and/or Vex in 5 of the main cities, Whiterun, Windhelm, Markath, Solitude and Riften. After you do the 5 quests then in that city you will have to do a special quest that will have the city respect the Theives guild more. You will get this quest from Delvin except the special quest for Riften you get after you do the other 4 cities. Make sure you do not sell any of the thieves armor they give you once you join because you get the achievement when Tonalia upgrades all of your armor to master status. An easy way to get all the quests done is by doing a bedlam quest from Delvin (steal items with a total value of 500 gold) at the same time doing the sweep quest from Vex (steal 3 items from a certain house). Make sure you get them both in the same city so you can knock out 2 birds with one stone. To make sure it is in the right city, save your game then talk to one of them until you get the city you want and then save again and make sure the other person gives you the same city. If you don't get the city you want then just load from the save before you get the quest from them. It will probably take a long time to get this one achievement after the Thieves quest (took me about 5 hours).