How could I write a text that would link to a paragraph in other page?
I assume that you want to insert a hyperlink so that if you control-click it you move to the target paragraph.
First you need to mark the paragraph with a bookmark. Place the cursor where you want the link to be and on the menu choose Insert/Bookmark. Give the bookmark a label.
Then insert a hyperlink that points to the bookmark. Select or type your hyperlink text, then on the menu choose Insert/Hyperlink, choose the Document icon on the left and type the label in the Target in document Target box. Apply and close.
When I insert the hyperlink, it changes my highlight text to the name of the bookmark. How do I preserve the original text?
I confirm this in Libreoffice 18.104.22.168 and 22.214.171.124. When Document is selected as the hyperlink destination in the Hyperlink dialog, the Text box in Further Settings is blanked. In Libreoffice 126.96.36.199 the selected text is kept in the Text box and is used as the hyperlink text. I’d call the new behavior a bug.
A work around is to copy the hyperlink text and paste it into the Hyperlink Further Settings Text box.
This particular bug is 86845.