How to draw horizontal ray lines on high/low of previous candle?

Question

I am trying to draw horizontal lines on high/low of previous candle on a specific timeframe. (I will call this "reference" timeframe)1H example

1. How do I code this so that this updates at every new candle in real time?
2. And how do I make it so that no matter what timeframe I choose afterward, the horizontal lines from the "reference" timeframe stays there. 1m example with 1H lines

I tried this code but this only applies to Daily timeframe as reference and I would like to be able to change the "reference" timeframe in the settings.

//@version=5
indicator("My script", overlay=true)

d_h = request.security(syminfo.tickerid, "D", high[1], lookahead=barmerge.lookahead_on)
d_l = request.security(syminfo.tickerid, "D", low[1], lookahead=barmerge.lookahead_on)

plot(d_h, style=plot.style_circles, color=color.green)
plot(d_l, style=plot.style_circles, color=color.red)