I've created a simple dataset (quite close to my original dataset) and posted the entire code for non reactive and reactive timeseries below. You know what .. it works with it haha ! I can change the inputs nicely.
Now I need to compare the two codes / datasets. Well we are progressing 
---
title: Global IG Efficiencies Dashboard
output:
flexdashboard::flex_dashboard:
vertical_layout: fill
runtime: shiny
---
```{r load-packages}
library(ggplot2)
library(magrittr)
library(tidyverse)
a<-LETTERS[seq(from = 1, to = 26)]
b<-seq(as.Date("2016/1/1"), by="month",length.out=26)
c<-c((rep("L1",13)),rep("L4",13))
d<-c((rep("LA",8)),rep("SQ",6),rep("VI",6),rep("RI",6))
e<-c((rep("SRC",13)),rep("REC",13))
f<-seq(20,200,length.out=26)
g<-seq(60,180,length.out=26)
h<-seq(65,85,length.out=26)
DF<- data.frame("Lot"=a, "Date"=b, "Line"=c, "Flavor"=d, "Plasma"=e, "Yield1"=f, "Yield2"=g, "Yield3"=h)
selectInput("input1", label = "Step",
choices = c("Yield1", "Yield2", "Yield3"), selected = "Yield3")
selectInput("input2", label = "Facility",
choices = c("LA", "VI", "RI", "SQ"), selected = "LA")
selectInput("input3", label = "Type",
choices = c("SRC", "REC"), selected = "SRC")
selectedData <- reactive({
DF %>% filter(Flavor == input$input2, Plasma == input$input3)
})
ggplot(DF,aes(Date, Yield3)) + geom_line(aes(color=Line)) + facet_wrap(~ Line)
renderPlot({
ggplot(selectedData(),aes_string("Date", input$input1)) + geom_line(aes_string(color="Line")) + facet_wrap(~ "Line")
})