Peetz: Here's a pic I grabbed off the 'net. Although the version is 1.11 - the items are the same. Opening the Downloadable Content menu item will list all DLC's loaded and the Options will allow you to turn on or off some of the features.
If you have the latest game version (1.12) ensure you download and install the latest DLC package as well from your GOG account.
ok in order i'll try to be clear. ill use that pic a reference
1. my in game verison is 1.12 gog is 1.12.1
2 there there is no downloadable content on my my menu
3. under the HoS banner is says avalible now instead of install. i have uninstalled and reinstalled both dlc packages three times now. one with a refresh install of the witcher 3
i trierd reverting back to 1.11 but got a server issue