Create a drop-down cell that brings information from other sheets on-click

Hi Everyone!

I am new to Excel and trying to find a way to do the following:
I have a Master List document which has several sheets (with information like - numbers codes et.). On the first Sheet I need to create somethin like a table and second row has to be a list where one can choose the desired department to display the data (that is on other sheets) related to that department.
P.S. when i create a list through data validation, i can't choose all the rows, or other sheets.

Below is the general look of the ML.
Capture.JPG

On the second row (A2), I need to display Department names, that you can choose, and after you choose one (let's say you choose Security Department), it brings all the info listed in SEC sheet for example to the SHEET1.
This info:
Capture2.JPG
To this sheet & cells.
Capture3.JPG

I am not sure if I could explain the problem clearly, as English is not my first language. Any help is appreciated. Thanks!

HOW TO ATTACH YOUR SAMPLE WORKBOOK: elgarnan, Fast answers need clear examples. Post a small Excel sheet (not a picture) showing realistic & representative sample data WITHOUT confidential information (10-20 rows, not thousands...) and some manually calculated results. For a new thread (1st post), scroll to Manage Attachments, otherwise scroll down to GO ADVANCED, click, and then scroll down to MANAGE ATTACHMENTS and click again. Now follow the instructions at the top of that screen.

Perhaps the following will help.
1. Populate cell G1 on Sheet1 using: =INDEX('List of Departments'!A2:A20,MATCH(A2,'List of Departments'!B2:B20,0))
2. Populate cells A3:E20 using: =INDIRECT($G$1&"!"&ADDRESS(ROWS(A$2:A4),COLUMNS($A3:A3)))
Note that cells A3:D20 are custom formatted: General;;
Note that cells E3:E20 are custom formatted: m/d/yyyy;;
Note that for this to work the codes on the List of Departments sheet must match the sheet tab names.
Let us know if you have any questions.

"I don't get how =INDIRECT($G$1&"!"&ADDRESS(ROWS(A$2:A4),COLUMNS($A3:A3))) is related to other sheets, perhaps trough INDEX&MATCH in G1?"
> Correct, but again for this to work the codes on the List of Departments sheet must match the sheet tab names and at the moment only the SEC and DSP codes match.
And how I can display empty cells to be empty instead of 0?
> Select cell A3 and press the Shift and right arrow keys until A3:D3 are selected and then press the Ctrl, Shift and down arrow keys
> Press the Ctrl and 1 keys
> Select Custom
> Under "Type:" the dialog box should display General, change that to display General;;
> Select cell E3 and press the Ctrl, Shift and down arrow keys
> Press the Ctrl and 1 keys
> Under "Type:" the dialog box should display m/d/yyyy, change that to display m/d/yyyy;;
Let us know if you have any questions.

You're Welcome. Thank You for the feedback and for marking the thread as 'Solved'. I hope that you have a blessed day.