You want it to display www.abc.com in the text or the panel?
1. if you want it for the text simply select this text and create a new hyperlink from the dialog. (Hyperlink panel click on the bottom New Hyperlink Button)
2. In the New Hyperlink dialog go to the URL tab and enter the URL you want it to point to actually (www.abc.com/abcdef/ghijklm/)
OK and it should work.
What version of InDesign are you using and also let us know the type of PDF you are generating Priont or Interactive
I'm using Indesign CC. Generating a print pdf.
have you turned on Hyperlinks check box in the PDF Export dialog. I tried with it and it was workign fine.
When ypou dont check this check box no URL is created in the PDF. But preview automatically sees this www.abc.com (since this is whats there in the document and no URL associated with it) it recognises this to be a URL and gives you this option.
Try turning on this check box and it should work, if not already had it turned on.