Basically the demand of Hamas and Hezbollah in respect of Israel is that it should allow a right of return for Palestinians who were forced to leave in 1948, and their families. Whether the resulting state would still choose to call itself Israel would be a matter for the population to decide for themselves. Defining this as "the destruction of the state of Israel" is rhetoric. I suppose the tearing down of the Berlin Wall was "the destruction of the GDR".

Anyway, this isn't an outcome that is too likely to come about. But it is not an unreasonable negotiating position. A negotiating position is something you bring to the negotiating table, not something you give ground on before negotiations are allowed to begin. Insisting on a demand like that is just a way of avoiding negotiations. To demand that Israel granted a right of return before any negotiations could begin would be a similar blocking manoeuvre.