Corel DESIGNER and CorelDRAW are based on the same application code and share many generic drawing tools.

However, besides the dedicated technical illustration tools, Corel DESIGNER also provides some unique UI behaviors that are different from the tools you find and the way you access them in CorelDRAW.

For example, Corel DESIGNER does not use Flyout tool bars.

The tool box in Corel DESIGNER, hosting all the drawing tools for any graphical element, displays the detailed tools at the bottom of the tool box (2) when selecting one of the (main) tools (1) in the tool box instead:

For certain technical illustration workflows this has some benefits.
Example: When creating dimensioning or callouts for a drawing, you normally draw multiple objects of that type in one sequence as a finishing step after the technical drawing has been completed.
Switching between aligned/ parallel, angular and radial dimension tools can be annoying with flyout tool bars that you need to click and expand every time to get the selection of tools that you want.

In Corel DESIGNER, you select the tool (i.e. dimension tools) once and then you have all the detailed dimension tools listed visibly in the tool box.
So you have those tools at hand for selecting the appropriate dimension tool for the next step with one click only.

However, if you prefer the classic flyout tool bars, you can still customize the Corel DESIGNER UI to provide that behavior: Go to Tools > Options... and navigate to Workspace > Toolbox in the Options dialog.
There you can select the "Display tool groups as flyout menus" option. Leaving the Options dialog with OK will change the behavior of the tool box immediately.