The Report Builder can be accessed by navigating to Administration > Report Builder. If you want to grant access to the Report Builder without giving access to the full Administration tab, you can do so by following these directions.

Go to Salesforce Setup Menu

Go to Salesforce Setup Menu

Access the Salesforce Setup menu in the upper right corner of your screen.
 

In the search box, type Tabs and then click Tabs under Create.

New Visualforce Tab

New Visualforce Tab

Scroll down to Visualforce Tabs and click New.

Step 1. Enter the Details

Visualforce Page: Report Builder [JBCXM_ReportBuilder]

Tab Label: Required and can be anything you want

Tab Name: Required and can be anything you want

Tab Style: Required and in this case we chose Pencil

Description: Optional

Click Next.

Step 2. Add to Profiles

Step 2. Add to Profiles

Choose which profiles to give access to. If you would prefer to give access at the Permission Set level, you will choose "Apply one tab visibility to all profiles" and choose Tab Hidden. Later you will need to set the tab access on the permission set.

Click Next.

Step 3. Add to Custom Apps

Step 3. Add to Custom Apps

Choose the custom apps for which the new custom tab will be available. You may also examine or alter the visibility of tabs from the detail and edit pages of each Custom App.

Click Save.

Note: Users will need access to the Visualforce page JBCXM_ReportBuilder via a permission set or profile permissions in order to access the tab with no errors.