Why can't I see member views in my form?

Have you deployed the model? After creating your member views and deploying they will show up as hierarchies in the AS cube and in the authoring UI? You may also need to refresh your system data in excel if you have deployed the model after opening/connecting from excel.

(Refresh system data is the default option of the refresh button on the ribbon or the action pane – I don’t have a tool installed to capture a screenshot of the popup menu today)