How to create report with nested accounts and custom object?

Question

I want to create a report that shows me details from all involved objects.

• The main object is an account (Record Type: 1).
• Each account is connected to one account (Record Type: 2) via a
  lookup.
• each account Type 1 can have only one account Type 2, but one Type 2 can get related to n Type 1 entries
• I have a custom object Timebook that is connected to a specific account (Type: 1)
• each account (Type 1) can have several Timebooks

Now I want to create a report showing the following:

• a list of all timebook entries, with related account details from both Type 1 and the related Type 2

I can display the details from timebook with account Type 1, but not the details from type 2, like address, mail and such.

I tried to create a joined report, but cannot add another account object.

Here is a schema of the involved objects:

Answer 1

Create a custom report type (Setup -> Create -> Report Types).

Call it "Accounts With Timesheets" or something like that, starting object would be Account. Relationship - I think it'd be best to set it to "with or without".

On the next page you'll be selecting fields to include (scroll down to the "Edit layout"). On the right side there will be blue "view" box with option to add fields related via lookup. You can use this to go from "Account Type 1" to it's parent "Account Type 2".

Add as many fields as you need, maybe also create a new section, call it "Parent Account" and move the new fields there (will be easier for users to identify which field they want to use in the report).

Notes:

1. The problem with custom report types is that they don't update automagically whenever you add a new field - standard report types are better. You'll have to remember to add new Account / Timesheet fields here whenever user comes to you couple weeks later that he can't report on something he'd like to see.
2. Report types can span over 3 objects (4 if there's Master-Detail involved). If there are some complex things under the Timesheet object you might decide to create a report type that starts from timesheet, goes down to these objects and you can always "go up" with this "add fields via lookup".
3. There's no easy way to transform report created with one report type to use another one. Plan ahead or you'll have to recreate them from scratch.