Set up the "menu" using a parameter.
From there you can find the index for the selected value and grab from -2 through +2 based on that index value.
Upload a sample workbook and we can work it together.
Also, I am using Tableau 10.5 just for your reference.
In the attached I made a parameter ([Item List]) that I populated with the values from [Item]. The user can select an item in the parameter.
Next I created a calc to find the index value for the selected item. See [Which item index ...]. I displayed that on your original sheet. You will notice that it only appears on the row of the item selected.
I made another calc to propagate that to all rows. See [Put index...]. I left this as two separate calcs to compartmentalize the steps, but you can nest these by wrapping the syntax in [Which item...] with the WINDOW_MAX( ) function, and it will all get done in one calc.
So as you select a value from the param, you'll see those numbers change accordingly.
Go to the copy of your sheet that I made for the next step.
Here I made a calc to filter so that we get 5 rows displayed (or up to 5 if the user selects a value where index = 1 or 2.) This just grabs the range you want to see. For the record, the rest of the rows are still in the underlying table (so that the index function still sees "Chocolate" as index = 6). When you use a table calc as a filter, it doesn't delete rows from the underlying table like a quick filter does. It just controls what part of the table to display. This is to allow other table calcs to function properly as you see here with the [index] table calc.
(If you needed to, you could take this a step further and make another calc to let the user choose the range to display, instead of hard-coding 2 in there. Just a suggestion.)
PS: Note that this is a very simple example. You have a simple TABLE(down) construct on the sheet, and Tableau properly interpreted that, and defaulted all the table calcs (anything with a triangle on the right end of the pill) to walk the table as TABLE(down). If you had a more complicated sheet, you might need to manually set the addressing of the table calcs. If you run into that and need help, let me know.
Example Book_v10.5.twbx 36.3 KB