For example, the replacement tag would become {NAV_TABLE_COLUMN
y}, where x is already there (integer equal to the structure value from where we want to start the menu), and where y would be an integer (default would be 0) that signifies how many levels deep would the menu already be expanded. So, let's say we have a site structure like this:
+Home
++Articles
++Pictures
+++Mountain
+++Seaside
++Comments
+Contacts
++Form
+About
The pluses mean that the structure level is a child, and it's parrent is the structure with one less plus (so Home, Contacts and About are the first level structures, Articles, Pictures,Comments are 2nd level, belonging to Home, and Form is the 2nd level belonging to Contacts, and Mountain and Seaside are 3rd level).
The current {NAV_TABLE_COLUMN:0} gives us this menu:
+Home
+Contacts
+About
{NAV_TABLE_COLUMN:0:0} produces the same effect, since 0 means that only the first structure level appears.
{NAV_TABLE_COLUMN:0:1} will expand (every time) every first structure level that has second structure levels; also, this means that these cannot be collapsed (so it's like a rigid normal menu); you will now have
+Home
++Articles
++Pictures
++Comments
+Contacts
++Form
+About
now the menu structure can only allow expansion/collapse on structures that have 3rd level types (Pictures in our case)
In a similar faction, {NAV_TABLE_COLUMN:0:2} would mean that the whole menu structure will self expand up to 2 levels deep, and give:
+Home
++Articles
++Pictures
+++Mountain
+++Seaside
++Comments
+Contacts
++Form
+About
so the entire structure already expanded (as i mentioned earlier, these cannot be collapsed anymore)
Also, it would be fine if only a total expansion features gets in, so you would either have normal, or totaly expanded menu (such as a sitemap starting from a given level, but with the features of highlighting the current child and all it's parents)
I hope you guys understand my explanation, I'm not a native english speaker, so tell me if you don't understand something.