@salmonmac has described it well.
Lift the green yarn from blue arrow and bring to where you need it, keeping it long enough to work back to where it has been picked up from (9 stitches ahead) to measure the correct length of yarn for this long float stretch out your stitches fully on both needles so you don’t not cause bunching by a too short float.
The green yarn is ‘attached’ to the yellow in the last stitch or 2 of the yellow by trapping it in behind the stitch (like in the video above). Now you have a green working yarn and a long green float. Catch the float behind the stitches as you work with the working yarn, both yarns are green but the method is the same as the video. The difference with the video is that the yarns are 2 different colours and the knitter has a lot of yarn to move around, you won’t have a lot of yarn as your float is already attached both ends, however you can still manipulate the float yarn in the same way, it only has to be lifted over the right needle as you work the new stitch.
Perhaps the confusion is that at each new part of your intarsia you are doing a full twist to connect the 2 Co,ours. This is fine and many tutorials show this, but I do not do this. Other methods do not create a full twist but just an interlock dropping the yarn to the left and picking up the new colour on the right (making a single cross over behind).
Looking at your chart, you will have the same or similar problem coming up on the next row where the the yellow will need to travel up from the row below and then across 9 stitches behind the work before it is introduced as the working yarn for the next yellow section. You will catch that yarn behind in the same way.
On my sample I did a lot more than 9 stitches and the float has not become too tight to work.
Another work around, again not “right”, is to tink back several stitches and work in a new piece of green, weaving in as you go across the tinked stitches so it is trapped in, then work it into your proper green yarn when you get there and weave in a tail. Again not perfect but a work around.
I had a horrible batch of badly dyed yarn and made half a sweater in little bits of yarn to avoid the problem areas and match up the self striping colours which meant dozens of short bits of yarn, tails all woven in as I went and sometimes I just worked a float behind to avoid a dirty section. The sweater has been washed and worn plenty and not fallen apart despite all the tails and weaving in.
I hope either salmonmacs description or this further explanation might help you work it out.
I know as a beginning knitter I wouldn’t want to tink back as far as you need just because my tinking skills were not so good. Although all these things are good practise to learn and improve our skills.