Sure you can do it. \hypertarget is overlay aware, so you can say something like
\hypertarget<4>{label}{\beamerbutton{I'm on the fourth slide}}
to place the target just on the fourth slide of a frame and then elsewhere use
\hyperlink{label}{\beamerbutton{I jump to fourth slide of next frame}}
to activate a button that will take you to the fourth slide previously targeted.
A complete example:
\documentclass{beamer}
\begin{document}
\begin{frame}
\hyperlink{label}{\beamerbutton{I jump to fourth slide of next frame}}
\end{frame}
\begin{frame}
\begin{itemize}[<+->]
\item First.
\item Second.
\item Third.
\item Fourth.\hypertarget<4>{label}{\beamerbutton{I'm on the fourth slide}}
\item Fifth.
\end{itemize}
\end{frame}
\end{document}
In your example, you can also use
\documentclass{beamer}
\begin{document}
\begin{frame}
\hyperlink{label}{\beamerbutton{I jump to fourth slide of next frame}}
\end{frame}
\begin{frame}
\only<4>{Some text\hypertarget{label}{\beamerbutton{I'm on the fourth slide}}}
\end{frame}
\end{document}
\hyperlinkoverlay aware? I mean, can I have a\hyperlink<6->{label}so that it would jump to the frame labeledlabelat overlay #6? – GertVdE Oct 09 '15 at 09:41\pauseinstead of standard overlays? – luchonacho Jan 15 '20 at 15:31\hyperlink<6->{label}creates a link that appears from the 6th slide. To jump to the frame at overlay #6 you can just add\hypertarget<6->into the frame title. – pip Dec 14 '20 at 17:28