What does a value like 12.4.8 represent? Is it a date? Is it even a number? Or is it text made up of digits (as in a Serial Number of a product)? If a number, what kind of number?
It might be -- and this is just a guess because you don't give enough information to do anything other than guess -- that what you should be doing in order to filter is to separate the cells in this single column into three separate columns [treat it as text, and use the text functions LEFT, MID and RIGHT to separate],, and apply the filters to those three separate columns.
But you'll need to come back with a much more complete description of what you're doing to get more than a guess.