Where do I go in the menu to make a Transparency in an image?

I know where the “Transparency” menu is but what it does is makes the whole image opaque or transparent, what I want is to remove the area around an image, for example imaging a circle that has a black line as the circle but the background and background of the circle are the same but I want to remove the white area from around the circle without affecting the inner circle…

I have tried help, searching on here but every subject leads back to what I don’t want, what I want is to be able to do what Macromedia Fireworks 8 allowed, the use of a wand tool to select the background, setting for the tolerance (amount of removed image) and then be left with a white circle with black outline and the remainder has gone, its transparent.

Libre Draw doesn’t have what I am looking for, using Help is no help because the information pertain to all Libre Office elements, not just Draw. Not at all helpful.

Can someone kindly explain how?

I gave up and cropped the image in GIMP and then removed the bits I didn’t want and then saved it as a PNG with a transparency.

Job done.