Access site column in Subsites

We have created a site collection and under it many sites and subsites, now our aim was to create some basic lists like state , city,country etc at the top level site and refer the same across all the subsites. We faced the problem ,where in a lookup column you can only refer the lists of current site. In order to add one of the columns from a Parent site list in a subsite list we did the following .
1. Create a site column. - In parent Site Go to Settings -> Site Column. Here Create a new site column and choose the type as Lookup. Get the Lookup Information from Another list and Select your Parent list and its realted Column.
2. Add site Column in your Subsite's list - Now go to your subsite list and goto list settings. Under Columns add a existing site column and select the above created custom column.
Hope it helps