Since the 2010 release, this dialog was accessible from the Render ribbon tab, on the flyout of the Camera panel, by selecting the Adjust tool, as seen below in its 2014 incarnation.
In AutoCAD® Architecture 2015, the Camera panel got a makeover, and the button styles of the Create Camera and Show Cameras tools were changed from Large with Text (Vertical) to Small With Text and stacked one above the other instead of being side-by-side. A blank third row was included, and the flyout eliminated, removing the Adjust tool with it.
Seems to me that the blank row is just crying out to have the Adjust tool placed there. The AECCAMERAADJUST command is still available in 2015; only the ribbon tool was omitted. Adding it back is quite easy, as can be seen in the Screencast below. Here is an outline of what I did - watch the video to see the specifics:
- Open the Customize User Interface dialog. [One way - type CUI and press the ENTER key at the Command: prompt; I selected Customize from the Workspace Switching tool pop-up menu on the Application Status Bar.]
- In the upper left pane, under the ACA node, expand the Ribbon node.
- Expand the Tabs node.
- Scroll down and expand the Render - ACA node. Make note that the actual name of the Camera panel is Render Camera - ACA. "Camera" is the display text.
- Expand the Panels node.
- Scroll down to the Render Camera - ACA node and expand it and the subnodes below it to examine its contents.
- Select the Render Camera - ACA node and verify the panel preview shows the correct panel. [There are often several similarly-named panels; checking for the actual panel name and verifying the preview can help prevent editing the incorrect panel.]
- In the lower left Command List pane, type adjust in the search box.
- Select the Adjust command from the list of search results.
- Verify that this is the correct command [AECCAMERAADJUST].
- Left-click, hold and drag the Adjust tool from the lower left pane up onto the upper left pane and drop it just below the Ribbon Control - Empty Row Aligner item under Row 3 of the Render Camera - ACA panel. Note that I find if I drag straight up to the upper left pane, the pane scrolls in unpredictable ways as the bottom boundary is crossed. That is why I take a somewhat circuitous route over the right panes, crossing over to the upper left pane from its right side. Also note that as you drag across the upper right pane, you will see blue markers to help indicate when you should drop the command. You want to have a blue line with short vertical lines at either end, right under the Ribbon Control - Empty Row Aligner item when you release the left mouse button.
- Select the Ribbon Control - Empty Row Aligner item, right click and choose Remove from the context menu.
- Select Yes when the alert dialog asks if you want to delete the element.
- In the upper left pane, select the newly added Adjust item.
- In the lower right pane, edit the properties of the Adjust tool. I chose to duplicate the properties that the 2014 version had. Refer to the image below the embedded Screencast if you do not have a previous version available.
- Select OK to dismiss the Customize User Interface dialog and ratify your edits.
- Wait for the program to process your changes, and then select the Render tab. You should see the amended Camera panel, with the added Adjust tool.
- Select the tool and verify that the Adjust Camera Position dialog opens.
Here are the properties of the Adjust tool in 2014.