Lookup with 2 variables - difficult to explain

I have seen in the AutoCAD help that you can have a "pass through" in a lookup table. but how do you do it?

I cant seem to find any info, its there but I just cant find it. please help.

I have attached a print screen from the help section to show what I am trying to do.

Looks to me as though someone has printed the manual incorrectly, the image shown is for a block properties table, and not for a lookup. If that is what you are trying to achieve then take a look for block properties table

Are you using Dynamic blocks in your drawing? Reverse look up will add a grip next to the block, when you click it, a list of values will be be shown.

Looks to me as though someone has printed the manual incorrectly, the image shown is for a block properties table, and not for a lookup. If that is what you are trying to achieve then take a look for block properties table

I'll have a look at properties tables. never used the, before - that is a screen shot from the help file in AutoCAD 2015, I checked the full version and its the same.

Are you using Dynamic blocks in your drawing? Reverse look up will add a grip next to the block, when you click it, a list of values will be be shown.

yeah I am using dynamic blocks, been using lookups for many different things, but if you have a look at the JPG I attached, it shows a reverse lookup with a scroll through to a second set of variables - i have never seen this done before nor have i found a way.

Yeah that it is how it is shown in the help files, unfortunately it is just plain wrong, someone used the wrong image in the help file which is misleading, that image is from a block properties table (it even says that in the image). This is the actual type of drop down you get from a lookup property